1. Field of the Invention
The invention relates to an image display method, an image coding apparatus, and an image decoding apparatus which are intended for distribution of image data capable of being separated into a plurality of elements.
2. Description of the Related Art
In recent years, the prevalence of such infrastructures as DVD media, digital broadcasting, and on-demand network communications has produced widespread use of digital contents. Since digital contents cause no degradation in quality even after duplication, copyright management is of high importance. Demands for legitimate protection of copyright on digital contents and other copyrighted materials are expected to grow in the future.
The number of digital contents accessible over the Internet is increasing year by year, and the number of Internet users is as well. This has resulted in an increasing amount of traffic on the Internet. In this respect, Japanese Patent Laid-Open Publication No. Hei 9-46677 discloses an image transmission apparatus which switches among a mode for transmitting only the I frames of MPEG data, a mode for transmitting the I frames and P frames of the same, and a mode for transmitting the I frames, P frames, and B frames of the same depending on the traffic on a transmission line.
Even with such a technique, however, various levels of demands that image providers and users have cannot be fully satisfied. For example, image providers aim for copyright protection and, at the same time, wish to have their contents shown to a large number of users. Meanwhile, users have various orientations ranging from high-end to price-sensitive.